ext4: Simplify last in leaf check in ext4_map_query_blocks

ext4: Simplify last in leaf check in ext4_map_query_blocks

This simplifies the check for last in leaf in ext4_map_query_blocks()
and fixes this cocci warning.

cocci warnings: (new ones prefixed by >>)
>> fs/ext4/inode.c:573:49-51: WARNING !A || A && B is equivalent to !A || B

Fixes: 5bb12b1837c0 ("ext4: Add support for EXT4_GET_BLOCKS_QUERY_LEAF_BLOCKS")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202505191524.auftmOwK-lkp@intel.com/
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://patch.msgid.link/5fd5c806218c83f603c578c95997cf7f6da29d74.1747677758.git.ritesh.list@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>