sstatesig.py: Replace '_'s with '-'s in SSTATE_LOCKEDSIGS* names.
Using underscores in the "types" parts of the variable names can cause
unexpected issues with overrides. For example, if you have both
SSTATE_LOCKEDSIGS_x86_64 and SSTATE_LOCKEDSIGS_x86_64_i586, and i586
is in OVERRIDES, then you lose all of the contents in
SSTATE_LOCKEDSIGS_x86_64 and thus don't get some of the locked sstate.
Using '-'s in the variable names instead, eliminates these issues.
(From OE-Core rev:
6662c412a949a9f6b602c848e6303b19db7e5272)
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
