lib: fix warning on little endian

* md5.c
  * md5_calc(): If building on little endian then X
    will be 'const uint32_t' which causes compiler
    warning in code that never gets used. Just move
    the endif to make sure code is not checked.
diff --git a/lib/md5.c b/lib/md5.c
index f1bd066..894de64 100644
--- a/lib/md5.c
+++ b/lib/md5.c
@@ -232,7 +232,7 @@
 	const uint32_t *X = (const uint32_t *)b64;
 #elif (BYTE_ORDER == BIG_ENDIAN)
 	uint32_t X[16];
-#endif
+
 	if (BYTE_ORDER == BIG_ENDIAN)
 	  {
 	    /* 4 byte words */
@@ -255,6 +255,7 @@
 	    y[56] = b64[59]; y[57] = b64[58]; y[58] = b64[57]; y[59] = b64[56];
 	    y[60] = b64[63]; y[61] = b64[62]; y[62] = b64[61]; y[63] = b64[60];
 	  }
+#endif
 
 	ROUND1(A, B, C, D,  0, Sa,  1); ROUND1(D, A, B, C,  1, Sb,  2);
 	ROUND1(C, D, A, B,  2, Sc,  3); ROUND1(B, C, D, A,  3, Sd,  4);