udf: initialize newblock to 0

stable inclusion
from stable-v5.10.195
commit 26f9ccb7a043ba203a534ed234e47841abe8ac9f
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I95JOC

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=26f9ccb7a043ba203a534ed234e47841abe8ac9f



--------------------------------

commit 23970a1c upstream.

The clang build reports this error
fs/udf/inode.c:805:6: error: variable 'newblock' is used uninitialized whenever 'if' condition is true [-Werror,-Wsometimes-uninitialized]
        if (*err < 0)
            ^~~~~~~~
newblock is never set before error handling jump.
Initialize newblock to 0 and remove redundant settings.

Fixes: d8b39db5fab8 ("udf: Handle error when adding extent to a file")
Reported-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Message-Id: <20221230175341.1629734-1-trix@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: sanglipeng <sanglipeng1@jd.com>