[docs][llvm-dwarfdump] Fix wording

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@365489 91177308-0d34-0410-b5e6-96231b3b80d8

Author: jh7370

docs/CommandGuide/llvm-dwarfdump.rst

@@ -77,7 +77,7 @@ OPTIONS
 
 .. option:: --lookup=<address>
 
-            Lookup <address> in the debug information and print out the file,
+            Look up <address> in the debug information and print out the file,
             function, block, and line table details.
 
 .. option:: -o <path>