Used external roborio compiler instead of local compiler.

Change-Id: Ifec0d68b0b51a822c906bc4f52320004ee2f5d84
diff --git a/frc971/control_loops/BUILD b/frc971/control_loops/BUILD
index 1fba54f..14799e4 100644
--- a/frc971/control_loops/BUILD
+++ b/frc971/control_loops/BUILD
@@ -65,7 +65,7 @@
   deps = [
     ':queues',
     ':gaussian_noise',
-    '//external:libm',
+    '//debian:libm',
   ],
 )
 
@@ -78,7 +78,7 @@
     'gaussian_noise.h',
   ],
   deps = [
-    '//external:libm',
+    '//debian:libm',
   ],
 )
 
@@ -93,7 +93,7 @@
   deps = [
     '//third_party/eigen',
     '//aos/common/controls:polytope',
-    '//external:libm',
+    '//debian:libm',
   ],
 )