Replace valloc() usages in portable code

valloc() is obsolete and 64-bit Android does not provide it at all. When
portability is required, use posix_memalign() instead.

Signed-off-by: Kim Topley <[email protected]>

Author: adierking

src/io.c

@@ -2312,7 +2312,10 @@ _dispatch_operation_perform(dispatch_operation_t op)
 			}
 			op->buf = _aligned_malloc(op->buf_siz, siInfo.dwPageSize);
 #else
-			op->buf = valloc(op->buf_siz);
+			err = posix_memalign(&op->buf, (size_t)PAGE_SIZE, op->buf_siz);
+			if (err != 0) {
+				goto error;
+			}
 #endif
 			_dispatch_op_debug("buffer allocated", op);
 		} else if (op->direction == DOP_DIR_WRITE) {