[dsymutil][NFC] Fix typo in help message

[ellis]

Summary

Just a simple typo fix that allows me to test landing a commit now that
I have commit access.

llvm/docs/CommandGuide/dsymutil.rst

  be returned if any architectures can not be properly linked.  This option can
  be specified multiple times, once for each desired architecture. All CPU
  architectures will be linked by default and any architectures that can't be
  properly linked will cause :program:`dsymutil` to return an error.
 
 .. option:: --dump-debug-map
 
  Dump the *executable*'s debug-map (the list of the object files containing the
- debug information) in YAML format and exit. Not DWARF link will take place.
+ debug information) in YAML format and exit. No DWARF link will take place.
 
 .. option:: --flat, -f
 
  Produce a flat dSYM file. A ``.dwarf`` extension will be appended to the
  executable name unless the output file is specified using the ``-o`` option.
 
 .. option:: --gen-reproducer
 

llvm/tools/dsymutil/Options.td

def no_swiftmodule_timestamp: F<"no-swiftmodule-timestamp">,
   HelpText<"Don't check timestamp for swiftmodule files.">,
   Group<grp_general>;
 
 def no_odr: F<"no-odr">,
   HelpText<"Do not use ODR (One Definition Rule) for type uniquing.">,
   Group<grp_general>;
 
 def dump_debug_map: F<"dump-debug-map">,
-  HelpText<"Parse and dump the debug map to standard output. Not DWARF link will take place.">,
+  HelpText<"Parse and dump the debug map to standard output. No DWARF link will take place.">,
   Group<grp_general>;
 
 def yaml_input: Flag<["-", "--"], "y">,
   HelpText<"Treat the input file is a YAML debug map rather than a binary.">,
   Group<grp_general>;
 
 def papertrail: F<"papertrail">,
   HelpText<"Embed warnings in the linked DWARF debug info.">,