If our pkg-config queries pass back a flag like -pthread, the trylink
script will expand that to -l-pthread. So change trylink to only add
the -l prefix to a value that doesn't have a - prefix already.
Reported-by: thaehaid@incognitomail.org
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
3eab2b7675