Suppress non-critical warnings in external/lmfit.

* We should enable those warnings after fixing the upstream source code.

Bug: 64487164
Test: build with WITH_TIDY=1

Change-Id: Id8645ccfea886e0d391c8829fbef6fdf33b38d8f
Merged-In: Id8645ccfea886e0d391c8829fbef6fdf33b38d8f
(cherry picked from commit b1e3bd9c344025ce81b94202a273fcd3286e4258)
diff --git a/Android.bp b/Android.bp
index a65d618..2bc9a21 100644
--- a/Android.bp
+++ b/Android.bp
@@ -21,5 +21,6 @@
         "lib/lmcurve_tyd.c",
         "lib/lmmin.c",
     ],
+    cflags: ["-W", "-Wall", "-Wno-unused-parameter"],
     export_include_dirs: ["lib"],
 }