Corrected typo in mips64.mk about memcpy.cpp

Change-Id: I1e6fb9373880bcdbad3fa86145e5138ce0d30b31
diff --git a/libc/arch-mips64/mips64.mk b/libc/arch-mips64/mips64.mk
index 9b29f0d..28c3d2b 100644
--- a/libc/arch-mips64/mips64.mk
+++ b/libc/arch-mips64/mips64.mk
@@ -60,7 +60,7 @@
 # FIXME TODO
 ## libc_bionic_src_files_mips64 += arch-mips64/string/memcpy.S
 ## libc_bionic_src_files_mips64 += arch-mips64/string/memset.S
-libc_bionic_src_files_mips64 += bionic/memcpy.c
+libc_bionic_src_files_mips64 += bionic/memcpy.cpp
 libc_bionic_src_files_mips64 += bionic/memset.c