[ Upstream commit 1dac6f5b0ed2601be21bb4e27a44b0c3e667b7f4 ]

gcc gets a bit confused by the logic in ovl_setup_trap() and
can't figure out whether the local 'trap' variable in the caller
was initialized or not:

fs/overlayfs/super.c: In function 'ovl_fill_super':
fs/overlayfs/super.c:1333:4: error: 'trap' may be used uninitialized in this function [-Werror=maybe-uninitialized]
    iput(trap);
    ^~~~~~~~~~
fs/overlayfs/super.c:1312:17: note: 'trap' was declared here

Reword slightly to make it easier for the compiler to understand.

Fixes: 146d62e5a586 ("ovl: detect overlapping layers")
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NMiklos Szeredi <mszeredi@redhat.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>