vcs-svn: suppress signed/unsigned comparison warnings

These are already safe because both sides of the comparison are
nonnegative.

This would normally not be important because Git is not -Wsign-compare
clean anyway, but we like to keep the vcs-svn/ lib to a higher
standard for convenience using it in other projects.

Signed-off-by: David Barr <davidbarr@google.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>

vcs-svn/fast_export.c

@@ -254,7 +254,7 @@ static int parse_ls_response(const char *response, uint32_t *mode,
 	}
 
 	/* Mode. */
-	if (response_end - response < strlen("100644") ||
+	if (response_end - response < (signed) strlen("100644") ||
 	    response[strlen("100644")] != ' ')
 		die("invalid ls response: missing mode: %s", response);
 	*mode = 0;
@@ -267,7 +267,7 @@ static int parse_ls_response(const char *response, uint32_t *mode,
 	}
 
 	/* ' blob ' or ' tree ' */
-	if (response_end - response < strlen(" blob ") ||
+	if (response_end - response < (signed) strlen(" blob ") ||
 	    (response[1] != 'b' && response[1] != 't'))
 		die("unexpected ls response: not a tree or blob: %s", response);
 	response += strlen(" blob ");