parser: Fix double-backslash nl in old-style command sub

When handling backslashes within an old-style command substitution,
we should not call pgetc_eatbnl because that would treat the next
backslash character as another escape character if it was then
followed by a new-line.

This patch fixes it by calling pgetc.

Reported-by: Matt Whitlock <dash@mattwhitlock.name>
Fixes: 6bbc71d84bea ("parser: use pgetc_eatbnl() in more places")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
1 file changed