Remove -Wno-uninitialized from libm Android.bp.

We can turn on -Wall too, if we turn off const-unused-variable and
unused-variable.

Bug: N/A
Test: builds
Change-Id: I8d889ea0acd334fbacbf7e707bcc2d0be633e4d5
diff --git a/libm/Android.bp b/libm/Android.bp
index 76a4699..9d318fa 100644
--- a/libm/Android.bp
+++ b/libm/Android.bp
@@ -515,12 +515,14 @@
         "-D_BSD_SOURCE",
         "-DFLT_EVAL_METHOD=0",
         "-include freebsd-compat.h",
+        "-Wall",
         "-Werror",
         "-Wno-missing-braces",
         "-Wno-parentheses",
         "-Wno-sign-compare",
-        "-Wno-uninitialized",
         "-Wno-unknown-pragmas",
+        "-Wno-unused-const-variable",
+        "-Wno-unused-variable",
     ],
 
     include_dirs: ["bionic/libc"],