src: Consistently spell whitespace without whitespace

Whitespace is spelled without a space between white and space, so
make sure to consistently spell it that way across the codebase.

Closes #6023
Reviewed-by: Daniel Stenberg <daniel@haxx.se>
Reviewed-by: Emil Engler <me@emilengler.com>

lib/checksrc.pl

@@ -52,7 +52,7 @@ my %warnings_extended = (
 my %warnings = (
     'LONGLINE'         => "Line longer than $max_column",
     'TABS'             => 'TAB characters not allowed',
-    'TRAILINGSPACE'    => 'Trailing white space on the line',
+    'TRAILINGSPACE'    => 'Trailing whitespace on the line',
     'CPPCOMMENTS'      => '// comment detected',
     'SPACEBEFOREPAREN' => 'space before an open parenthesis',
     'SPACEAFTERPAREN'  => 'space after open parenthesis',
@@ -399,7 +399,7 @@ sub scanfile {
             checkwarn("TABS",
                       $line, length($1), $file, $l, "Contains TAB character", 1);
         }
-        # detect trailing white space
+        # detect trailing whitespace
         if($l =~ /^(.*)[ \t]+\z/) {
             checkwarn("TRAILINGSPACE",
                       $line, length($1), $file, $l, "Trailing whitespace");

lib/curl_path.c

@@ -168,7 +168,7 @@ CURLcode Curl_get_pathname(const char **cpp, char **path, char *homedir)
     *cpp = cp + i + strspn(cp + i, WHITESPACE);
   }
   else {
-    /* Read to end of filename - either to white space or terminator */
+    /* Read to end of filename - either to whitespace or terminator */
     end = strpbrk(cp, WHITESPACE);
     if(end == NULL)
       end = strchr(cp, '\0');
@@ -184,7 +184,7 @@ CURLcode Curl_get_pathname(const char **cpp, char **path, char *homedir)
       (*path)[pathLength] = '\0';
       cp += 3;
     }
-    /* Copy path name up until first "white space" */
+    /* Copy path name up until first "whitespace" */
     memcpy(&(*path)[pathLength], cp, (int)(end - cp));
     pathLength += (int)(end - cp);
     (*path)[pathLength] = '\0';

lib/ftplistparser.c

@@ -418,8 +418,8 @@ size_t Curl_ftp_parselist(char *buffer, size_t size, size_t nmemb,
             finfo->b_data[parser->item_length - 1] = 0;
             if(strncmp("total ", finfo->b_data, 6) == 0) {
               char *endptr = finfo->b_data + 6;
-              /* here we can deal with directory size, pass the leading white
-                 spaces and then the digits */
+              /* here we can deal with directory size, pass the leading
+                 whitespace and then the digits */
               while(ISSPACE(*endptr))
                 endptr++;
               while(ISDIGIT(*endptr))

lib/http.c

@@ -1355,7 +1355,7 @@ Curl_compareheader(const char *headerline, /* line to check */
   /* pass the header */
   start = &headerline[hlen];
 
-  /* pass all white spaces */
+  /* pass all whitespace */
   while(*start && ISSPACE(*start))
     start++;