msm: rpm-regulator-smd: remove incorrect rpm_regulator_get() unlock calls

The rpm_regulator_get() function calls rpm_vreg_unlock() in
failure paths after two kzalloc() calls.  However, there is no
corresponding rpm_vreg_lock() call before these calls.  Also, the
code being executed does not require mutual exclusion.  Thus,
remove the rpm_vreg_unlock() calls in order to avoid possible
locking problems if kzalloc() fails.

Change-Id: I0a0f2ffde5a6c54600a823e3ed12c3c47c3bac6a
Signed-off-by: David Collins <collinsd@codeaurora.org>