ext4: standardize error handling in ext4_da_write_inline_data_begin()

The function has a bit non-standard (for ext4) error recovery in that it
used a mix of 'out' labels and testing for 'handle' being NULL. There
isn't a good reason for that in the function so clean it up a bit.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>