libcrypt: shrink crypt() again - unmodularise

modularisation added too much bloat for no benefit, undo.

$ ../busybox/scripts/bloat-o-meter .lib.05/libcrypt-0.9.33-rc1-git.so lib/libcrypt-0.9.33-rc1-git.so
function                                             old     new   delta
crypt                                                130      46     -84
.rodata                                             2704       -   -2704
------------------------------------------------------------------------------
(add/remove: 0/1 grow/shrink: 0/1 up/down: 0/-2788)         Total: -2788 bytes

Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>

libcrypt/crypt.c

@@ -6,43 +6,26 @@
  */
 
 #define __FORCE_GLIBC
-#include <crypt.h>
 #include <unistd.h>
-#include <string.h>
-#include <errno.h>
+#include <crypt.h>
 #include "libcrypt.h"
 
-typedef char *(*crypt_impl_f)(const unsigned char *pw, const unsigned char *salt);
-
-static const struct {
-	const char *salt_pfx;
-	const crypt_impl_f crypt_impl;
-} crypt_impl_tab[] = {
-	{ "$1$",        __md5_crypt },
-#ifdef __UCLIBC_HAS_SHA256_CRYPT_IMPL__
-	{ "$5$",        __sha256_crypt },
-#endif
-#ifdef __UCLIBC_HAS_SHA512_CRYPT_IMPL__
-	{ "$6$",        __sha512_crypt },
-#endif
-	{ NULL,         __des_crypt },
-};
-
 char *crypt(const char *key, const char *salt)
 {
 	const unsigned char *ukey = (const unsigned char *)key;
 	const unsigned char *usalt = (const unsigned char *)salt;
-	size_t i;
-
-	for (i = 0; i < ARRAY_SIZE(crypt_impl_tab); i++) {
-		if (crypt_impl_tab[i].salt_pfx != NULL &&
-		    strncmp(crypt_impl_tab[i].salt_pfx, salt, strlen(crypt_impl_tab[i].salt_pfx)))
-			continue;
 
-		return crypt_impl_tab[i].crypt_impl(ukey, usalt);
+	if (salt[0] == '$' && salt[2] == '$') {
+		if (*++salt == '1')
+			return __md5_crypt(ukey, usalt);
+#ifdef __UCLIBC_HAS_SHA256_CRYPT_IMPL__
+		else if (*salt == '5')
+			return __sha256_crypt(ukey, usalt);
+#endif
+#ifdef __UCLIBC_HAS_SHA512_CRYPT_IMPL__
+		else if (*salt == '6')
+			return __sha512_crypt(ukey, usalt);
+#endif
 	}
-
-	/* no crypt implementation was found, set errno to ENOSYS and return NULL */
-	__set_errno(ENOSYS);
-	return NULL;
+	return __des_crypt(ukey, usalt);
 }