validate: Clean GMP trees

For reasons unknown `validate` passed `NO_CLEAN_GMP=YES` to
`maintainer-clean`, leaving a stale `gmp.h` which causes the build to
fail in the event that the uses a tree for validating for two different
target platforms. This is quite unexpected, don't do it.

Reviewers: hvr, austin, rwbarton, dfeuer

Reviewed By: dfeuer

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D3409

1 files changed, 1 insertions, 1 deletions

diff --git a/validate b/validate
index 8caa0e2b89..09f4fd2f23 100755
--- a/validate
+++ b/validate
@@ -176,7 +176,7 @@ if [ $testsuite_only -eq 0 ]; then
 thisdir=`pwd`
 
 if [ $no_clean -eq 0 ]; then
-    $make maintainer-clean NO_CLEAN_GMP=YES
+    $make maintainer-clean
 
     INSTDIR="$thisdir/inst"