lto: Remove random_seed from section name.

This patch removes suffixes from section names during LTO linking.

These suffixes were originally added for ld -r to work (PR lto/44992).
They were added to all LTO object files, but are only useful before WPA.
After that they waste space, and if kept random, make LTO caching impossible.

Bootstrapped/regtested on x86_64-pc-linux-gnu

gcc/ChangeLog:

	* lto-streamer.cc (lto_get_section_name): Remove suffixes after WPA.

gcc/lto/ChangeLog:

	* lto-common.cc (lto_section_with_id): Dont load suffix during LTRANS.