MXS-1618 Use right type for the return value of getopt_long

getopt_long returns an 'int'. If 'char' is used on a big-endian
platform you'll end up with an infinite loop.

client/maxadmin.c

@@ -142,7 +142,7 @@ main(int argc, char **argv)
     bool use_unix_socket = false;
 
     int option_index = 0;
-    char c;
+    int c;
     while ((c = getopt_long(argc, argv, "h:p::P:u:S:v?ei",
                             long_options, &option_index)) >= 0)
     {

server/modules/routing/binlogrouter/maxbinlogcheck.c

@@ -86,7 +86,7 @@ int main(int argc, char **argv)
     char *key_file = NULL;
     char *aes_algo = NULL;
     int report_header = 0;
-    char c;
+    int c;
 
     while ((c = getopt_long(argc, argv, "dVfMHK:A:?", long_options, &option_index)) >= 0)
     {