OpenCL: properly initiate a mask buffer

The buffer must be initialized with zeros since it is used to calculate
the position where the character will be placed in the mask expansion.
SHA256 and SHA512 (crude).

Author: claudioandre-br

src/opencl_rawsha256_fmt_plug.c

@@ -261,7 +261,7 @@ static void create_clobj(size_t gws, struct fmt_main *self)
 	//Assure buffers have no "trash data".
 	memset(plaintext, '\0', BUFFER_SIZE * gws);
 	memset(saved_idx, '\0', sizeof(uint32_t) * gws);
-	memset(saved_int_key_loc, 0x80, sizeof(uint32_t) * mask_gws);
+	memset(saved_int_key_loc, '\0', sizeof(uint32_t) * mask_gws);
 }
 
 static void release_clobj()

src/opencl_rawsha512_gpl_fmt_plug.c

@@ -293,7 +293,7 @@ static void create_clobj(size_t gws, struct fmt_main *self)
 	//Assure buffers have no "trash data".
 	memset(plaintext, '\0', BUFFER_SIZE * gws);
 	memset(saved_idx, '\0', sizeof(uint32_t) * gws);
-	memset(saved_int_key_loc, 0x80, sizeof(uint32_t) * mask_gws);
+	memset(saved_int_key_loc, '\0', sizeof(uint32_t) * mask_gws);
 }
 
 static void release_clobj()