[llvm-objdump] Rename --disassemble-functions to --disassemble-symbols

https://bugs.llvm.org/show_bug.cgi?id=41910

The feature can disassemble data and the new option name reflects its
more generic usage.

Reviewed By: jhenderson

Differential Revision: https://reviews.llvm.org/D75816
diff --git a/llvm/docs/CommandGuide/llvm-objdump.rst b/llvm/docs/CommandGuide/llvm-objdump.rst
index 1b8273b..2730374 100644
--- a/llvm/docs/CommandGuide/llvm-objdump.rst
+++ b/llvm/docs/CommandGuide/llvm-objdump.rst
@@ -33,7 +33,7 @@
 
   Disassemble all sections found in the input files.
   
-.. option:: --disassemble-functions=<symbol1[,symbol2,...]>
+.. option:: --disassemble-symbols=<symbol1[,symbol2,...]>
 
   Disassemble only the specified symbols. Takes demangled symbol names when
   :option:`--demangle` is specified, otherwise takes mangled symbol names.