Don't reuse variable name in the loop to fix adding extra compiler flags via toolchainopts

[branfosj]

(created using eb --new-pr)

With: toolchainopts = {'opt': True, 'extra_cxxflags': '-ip'} we currently get:

F90FLAGS=-O3 -xHost -ftz -fp-speculation=safe -fp-model source -- -i -p
CXXFLAGS=-O3 -xHost -ftz -fp-speculation=safe -fp-model source -ip
FCFLAGS=-O3 -xHost -ftz -fp-speculation=safe -fp-model source -- -i -p
FFLAGS=-O3 -xHost -ftz -fp-speculation=safe -fp-model source -- -i -p
CFLAGS=-O3 -xHost -ftz -fp-speculation=safe -fp-model source

[boegel]

lgtm

[akesandgren]

And yes it clearly fixes the problem.

[akesandgren]

LGTM

[akesandgren]

Going in, thanks @branfosj!