Rename warning -> warn.

It's better because it's a verb.

llvm-svn: 282763
diff --git a/lld/ELF/Relocations.cpp b/lld/ELF/Relocations.cpp
index 61fb1dd..3f58f95 100644
--- a/lld/ELF/Relocations.cpp
+++ b/lld/ELF/Relocations.cpp
@@ -269,7 +269,7 @@
     return ((read32<E>(BufLoc) & 0xffff) << 16) +
            readSignedLo16<E>(Buf + RI->r_offset);
   }
-  warning("can't find matching " + getRelName(Type) + " relocation for " +
+  warn("can't find matching " + getRelName(Type) + " relocation for " +
           getRelName(Rel->getType(Config->Mips64EL)));
   return 0;
 }