remoteproc: fix various checkpatch warnings

Fix all the checkpatch warnings in the core remoteproc
code. The fixes cover the following warnings:
  1. WARNING: void function return statements are not generally useful
  2. WARNING: Possible unnecessary 'out of memory' message
  3. WARNING: line over 80 characters
  4. WARNING: braces {} are not necessary for single statement blocks
  5. WARNING: Unnecessary space before function pointer arguments

Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>