posix: device_io: mark pwrite() buf as const

match standard by having input void *buf parameter
for pwrite() marked as const, and avoid any potential
declaration conflicts

Signed-off-by: Nicholas Lowell <Nicholas.Lowell@lexmark.com>

Author: Nicholas Lowell

lib/posix/options/device_io.c

@@ -99,7 +99,7 @@ int pselect(int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
 	return zvfs_select(nfds, readfds, writefds, exceptfds, timeout, sigmask);
 }
 
-ssize_t pwrite(int fd, void *buf, size_t count, off_t offset)
+ssize_t pwrite(int fd, const void *buf, size_t count, off_t offset)
 {
 	size_t off = (size_t)offset;