jbd2: Update locking coments
jbd2: Update locking coments

Update information about locking in JBD2 revoke code. Inconsistency in
comments found by Lin Tan <103dd4fb5c92e618beffdb276aa68d675a61a1f2@gmail.com>.

CC: Lin Tan <103dd4fb5c92e618beffdb276aa68d675a61a1f2@gmail.com>.
Signed-off-by: Jan Kara <596727c8a0ea4db3ba2ceceedccbacd3d7b371b8@suse.cz>
Signed-off-by: "Theodore Ts'o" <4ed386e0495d3e109932df055831d9ec2f824927@mit.edu>

KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas