[libc] remove useless headers

GitOrigin-RevId: 00ba1a3de7faad80f7bb75d07a1a5da09a009895
diff --git a/src/string/memcpy.h b/src/string/memcpy.h
index 39ca4a4..f643f1d 100644
--- a/src/string/memcpy.h
+++ b/src/string/memcpy.h
@@ -9,7 +9,6 @@
 #ifndef LLVM_LIBC_SRC_STRING_MEMCPY_H
 #define LLVM_LIBC_SRC_STRING_MEMCPY_H
 
-#include "include/string.h"
 #include <stddef.h> // size_t
 
 namespace __llvm_libc {
diff --git a/src/string/memset.h b/src/string/memset.h
index 611e707..e38eb7d 100644
--- a/src/string/memset.h
+++ b/src/string/memset.h
@@ -9,7 +9,7 @@
 #ifndef LLVM_LIBC_SRC_STRING_MEMSET_H
 #define LLVM_LIBC_SRC_STRING_MEMSET_H
 
-#include "include/string.h"
+#include <stddef.h> // size_t
 
 namespace __llvm_libc {