[lld/elf] Use C++17 nested namespace syntax in most places
Like D131405, but for ELF.
No behavior change.
Differential Revision: https://reviews.llvm.org/D131612
diff --git a/lld/ELF/MapFile.h b/lld/ELF/MapFile.h
index 36bd1d2..b271f62 100644
--- a/lld/ELF/MapFile.h
+++ b/lld/ELF/MapFile.h
@@ -9,10 +9,8 @@
#ifndef LLD_ELF_MAPFILE_H
#define LLD_ELF_MAPFILE_H
-namespace lld {
-namespace elf {
+namespace lld::elf {
void writeMapAndCref();
-} // namespace elf
-} // namespace lld
+}
#endif
