ext4: fix memory leak in ext4_ext_shift_extents()

In the Linux kernel, the following vulnerability has been resolved:

ext4: fix memory leak in ext4_ext_shift_extents()

In ext4_ext_shift_extents(), if the extent is NULL in the while loop, the

function returns immediately without releasing the path obtained via

ext4_find_extent(), leading to a memory leak.

Fix this by jumping to the out label to ensure the path is properly

released.