KVM: x86/mmu: Clean up mmu.c functions that put return type on separate line

KVM: x86/mmu: Clean up mmu.c functions that put return type on separate line

Adjust a variety of functions in mmu.c to put the function return type on
the same line as the function declaration.  As stated in the Linus
specification:

  But the "on their own line" is complete garbage to begin with. That
  will NEVER be a kernel rule. We should never have a rule that assumes
  things are so long that they need to be on multiple lines.

  We don't put function return types on their own lines either, even if
  some other projects have that rule (just to get function names at the
  beginning of lines or some other odd reason).

Leave the functions generated by BUILD_MMU_ROLE_REGS_ACCESSOR() as-is,
that code is basically illegible no matter how it's formatted.

No functional change intended.

Link: https://lore.kernel.org/mm-commits/CAHk-=wjS-Jg7sGMwUPpDsjv392nDOOs0CtUtVkp=S6Q7JzFJRw@mail.gmail.com
Signed-off-by: Ben Gardon <bgardon@google.com>
Link: https://lore.kernel.org/r/20230202182809.1929122-4-bgardon@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>