nvme: fix overflow possiblity

The implicit type conversion will expand both operands to the type
int and not unsigned long long as the result expects. Promote
the first operand to the target type. Obviously the multiplication
can still overflow, but this is a different problem.

Signed-off-by: Steven Seungcheol Lee <[email protected]>
[dwagner: added commit message]
Signed-off-by: Daniel Wagner <[email protected]>

nvme.c

@@ -7317,7 +7317,7 @@ static int submit_io(int opcode, char *command, const char *desc, int argc, char
 		nblocks = ((buffer_size + (logical_block_size - 1)) / logical_block_size) - 1;
 
 		/* Update the data size based on the required block count */
-		buffer_size = (nblocks + 1) * logical_block_size;
+		buffer_size = ((unsigned long long)nblocks + 1) * logical_block_size;
 	}
 
 	buffer = nvme_alloc_huge(buffer_size, &huge);