Document --print-needed

`--help` output has already.

Author: klemensn

patchelf.1

@@ -85,6 +85,9 @@ This option can be given multiple times.
 Removes a declared dependency on LIBRARY (DT_NEEDED entry). This
 option can be given multiple times.
 
+.IP --print-needed
+Prints all DT_NEEDED entries of the executable.
+
 .IP "--no-default-lib"
 Marks the object so that the search for dependencies of this object will ignore any
 default library search paths.