Fix pwdx argument parsing

On some architectures/gcc's, the pwdx tool doesn't compile right
because of bad type of a variable. Afterwards pwdx can't be
persuaded to work. Use int as the type, like the other tools
(like pgrep) do.

Signed-off-by: Craig Small <csmall@enc.com.au>

pwdx.c

@@ -63,7 +63,7 @@ int check_pid_argument(char *input)
 
 int main(int argc, char *argv[])
 {
-	char ch;
+	int ch;
 	int retval = 0, i;
 	int alloclen = 128;
 	char *pathbuf;