[committed] Remove a redundant condition check in tic6x-linux-tdep.c

[Tom Tromey]

>>>>> "Yao" == Yao Qi <yao@codesourcery.com> writes:

Yao> This patch is to change function tic6x_register_sigcontext_offset,
Yao> which is to get the input REGNUM, and return the offset of
Yao> corresponding register in 'struct sigcontext'.  So -1 means 'all
Yao> registers' doesn't apply here.

Yao> Thank for reminding me this, I don't know -1 means 'all registers' before.

I suppose it is possible to change all the unsigned ints to ints in that
spot, but overall I think it is clearer with unsigned.

Tom