nfsd: more robust allocation failure handling in nfsd_file_cache_init

nfsd: more robust allocation failure handling in nfsd_file_cache_init

BugLink: https://bugs.launchpad.net/bugs/1969110
[ Upstream commit 4d2eeafecd6c83b4444db3dc0ada201c89b1aa44 ]

The nfsd file cache table can be pretty large and its allocation
may require as many as 80 contigious pages.

Employ the same fix that was employed for similar issue that was
reported for the reply cache hash table allocation several years ago
by commit 8f97514b423a ("nfsd: more robust allocation failure handling
in nfsd_reply_cache_init").

Fixes: 65294c1f2c5e ("nfsd: add a new struct file caching facility to nfsd")
Link: https://lore.kernel.org/linux-nfs/e3cdaeec85a6cfec980e87fc294327c0381c1778.camel@kernel.org/
Suggested-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
(cherry picked from commit cc91880f041705062aab4cc1d4e1271f4ecabd08)
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>