[docs][llvm-dwarfdump] Normalise some wording

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@365603 91177308-0d34-0410-b5e6-96231b3b80d8

docs/CommandGuide/llvm-dwarfdump.rst

@@ -25,7 +25,7 @@ OPTIONS
 
 .. option:: -a, --all
 
-            Disassemble all supported DWARF sections.
+            Dump all supported DWARF sections.
 
 .. option:: --arch=<arch>