K 10
svn:author
V 2
bz
K 8
svn:date
V 27
2020-09-04T18:18:05.443026Z
K 7
svn:log
V 541
cam_sim: harmonize code related to acquiring a mtx

cam_sim_free(), cam_sim_release(), and cam_sim_hold() all assign
a mtx variable during declaration and then if NULL or the mtx is
held may re-asign the variable and/or acquire/release a lock.

Harmonize the code, avoiding double assignments and make it look
the same for all three function (with cam_sim_free() not needing
an extra case).

No functional changes intended.

Reviewed by:	imp; no-objections by: mav
MFC after:	3 days
Differential Revision:	https://reviews.freebsd.org/D26286

END