jfs: remove redundant initialization to pointer ip

The pointer ip is being initialized with a value that is never read, it
is being re-assigned later on. The assignment is redundant and can be
removed.  Cleans up clang scan warning:

fs/jfs/namei.c:886:16: warning: Value stored to 'ip' during its
initialization is never read [deadcode.DeadStores]

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>