x86/mm: Rename set_memory_present() to set_memory_p()

Have it adhere to the naming convention for those helpers.

No functional changes.

Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20220805140702.31538-1-bp@alien8.de


Signed-off-by: Ingo Molnar <mingo@kernel.org>