preproc: avoid dropping the facility name in %pragma
preproc: avoid dropping the facility name in %pragma

tline got advanced a token too far, with the obvious results that the
facility name got truncated. Skip whitespace *after* expand_smacro(),
not before.

Signed-off-by: H. Peter Anvin <8a453bad9912ffe59bc0f0b8abe03df9be19379e@zytor.com>

techkey/nasm,techkey/nasm,techkey/nasm,techkey/nasm,techkey/nasm