mountd: remove a bogus include to fix compile with musl

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

SVN-Revision: 41062

package/system/mountd/patches/050-no_error_h.patch

+--- a/lib/fs.c
++++ b/lib/fs.c
+@@ -2,7 +2,6 @@
+ #include <unistd.h>
+ #include <stdlib.h>
+ #include <string.h>
+-#include <error.h>
+ #include <sys/types.h>
+ #include <sys/stat.h>
+ #include <fcntl.h>