As part of my work on the Linux Kernel Janitors project, cleaning up on
  functions which call misc_register and don't check for an error return, I
  would like to submit my patch to drivers/parisc/kernel/perf.c

  This patch simply causes the function to printk() an error and return the
  error code from misc_register() if it fails. I hope this is the right
  thing to do. I moved it slightly earlier in the function so I wouldn't
  have to worry about undoing the side effects of perf_patch_images().