regulator: core: Fix nested locking of supplies

commit 70a7fb80e85a ("regulator: core: Fix nested locking of supplies")

Commit fa731ac7ea04 ("regulator: core: avoid unused variable warning")
introduced a subtle change in how supplies are locked. Where previously
code was always locking the regulator of the current iteration, the new
implementation only locks the regulator if it has a supply. For any
given power tree that means that the root will never get locked.

On the other hand the regulator_unlock_supply() will still release all
the locks, which in turn causes the lock debugging code to warn about a
mutex being unlocked which wasn't locked.

Cc: Mark Brown <broonie@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Fixes: fa731ac7ea04 ("regulator: core: avoid unused variable warning")
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Git-commit: 70a7fb80e85ae7f78f8e90cec3fbd862ea6a4d4b
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git


[ashayj@codeaurora.org: Fix the regulator bug which was re-introduced by
commit f145f4]

CRs-Fixed: 1065539
Change-Id: I376a6412bb65a1e193647eab54ad993df4c2c24f
Signed-off-by: Ashay Jaiswal <ashayj@codeaurora.org>