MDEV-7942: InnoDB: abuse of UNIV_LIKELY()/UNIV_UNLIKELY()

UNIV_LIKELY()/UNIV_UNLIKELY() hints are supposed to improve branch prediction.
Currently, they're expected to work only if cond evaluates to TRUE or FALSE.

However there're a few conditions that may evaluate to different values, e.g.:

page/page0zip.cc:		if (UNIV_LIKELY(c_stream->avail_in)) {
page/page0zip.cc:			if (UNIV_LIKELY(c_stream->avail_in)) {
dict/dict0mem.cc:		if (UNIV_LIKELY(i) && UNIV_UNLIKELY(!table->col_names)) {

Fixed these conditions so that they evaluate TRUE/FALSE.

storage/innobase/dict/dict0mem.cc

@@ -285,7 +285,7 @@ dict_mem_table_add_col(
 		if (UNIV_UNLIKELY(table->n_def == table->n_cols)) {
 			heap = table->heap;
 		}
-		if (UNIV_LIKELY(i) && UNIV_UNLIKELY(!table->col_names)) {
+		if (UNIV_LIKELY(i != 0) && UNIV_UNLIKELY(table->col_names == NULL)) {
 			/* All preceding column names are empty. */
 			char* s = static_cast<char*>(
 				mem_heap_zalloc(heap, table->n_def));

storage/innobase/page/page0zip.cc

@@ -923,7 +923,7 @@ page_zip_compress_sec(
 			rec - REC_N_NEW_EXTRA_BYTES
 			- c_stream->next_in);
 
-		if (UNIV_LIKELY(c_stream->avail_in)) {
+		if (UNIV_LIKELY(c_stream->avail_in != 0)) {
 			UNIV_MEM_ASSERT_RW(c_stream->next_in,
 					   c_stream->avail_in);
 			err = deflate(c_stream, Z_NO_FLUSH);
@@ -1018,7 +1018,7 @@ page_zip_compress_clust_ext(
 
 			c_stream->avail_in = static_cast<uInt>(
 				src - c_stream->next_in);
-			if (UNIV_LIKELY(c_stream->avail_in)) {
+			if (UNIV_LIKELY(c_stream->avail_in != 0)) {
 				err = deflate(c_stream, Z_NO_FLUSH);
 				if (UNIV_UNLIKELY(err != Z_OK)) {
 

storage/xtradb/dict/dict0mem.cc

@@ -301,7 +301,7 @@ dict_mem_table_add_col(
 		if (UNIV_UNLIKELY(table->n_def == table->n_cols)) {
 			heap = table->heap;
 		}
-		if (UNIV_LIKELY(i) && UNIV_UNLIKELY(!table->col_names)) {
+		if (UNIV_LIKELY(i != 0) && UNIV_UNLIKELY(table->col_names == NULL)) {
 			/* All preceding column names are empty. */
 			char* s = static_cast<char*>(
 				mem_heap_zalloc(heap, table->n_def));

storage/xtradb/page/page0zip.cc

@@ -912,7 +912,7 @@ page_zip_compress_sec(
 			rec - REC_N_NEW_EXTRA_BYTES
 			- c_stream->next_in);
 
-		if (UNIV_LIKELY(c_stream->avail_in)) {
+		if (UNIV_LIKELY(c_stream->avail_in != 0)) {
 			UNIV_MEM_ASSERT_RW(c_stream->next_in,
 					   c_stream->avail_in);
 			err = deflate(c_stream, Z_NO_FLUSH);
@@ -1007,7 +1007,7 @@ page_zip_compress_clust_ext(
 
 			c_stream->avail_in = static_cast<uInt>(
 				src - c_stream->next_in);
-			if (UNIV_LIKELY(c_stream->avail_in)) {
+			if (UNIV_LIKELY(c_stream->avail_in != 0)) {
 				err = deflate(c_stream, Z_NO_FLUSH);
 				if (UNIV_UNLIKELY(err != Z_OK)) {