docsrc: fix crc32hash type

Fix differing signedness warning:

Documentation/pcmcia/crc32hash.c:29: warning: pointer targets in passing argument 1 of 'crc32' differ in signedness
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Acked-by: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Documentation/pcmcia/crc32hash.c

@@ -26,7 +26,7 @@ int main(int argc, char **argv) {
 		printf("no string passed as argument\n");
 		return -1;
 	}
-	result = crc32(argv[1], strlen(argv[1]));
+	result = crc32((unsigned char const *)argv[1], strlen(argv[1]));
 	printf("0x%x\n", result);
 	return 0;
 }