Fix -yy documentation

* strace.c (usage): Fix description of -yy option.
* strace.1: Likewise.

strace.1

@@ -325,7 +325,7 @@ Print all strings in hexadecimal string format.
 Print paths associated with file descriptor arguments.
 .TP
 .B \-yy
-Print ip:port pairs associated with socket file descriptors.
+Print protocol specific information associated with socket file descriptors.
 .TP
 .BI "\-a " column
 Align return values in a specific column (default column 40).

strace.c

@@ -218,7 +218,7 @@ Output format:\n\
   -x             print non-ascii strings in hex\n\
   -xx            print all strings in hex\n\
   -y             print paths associated with file descriptor arguments\n\
-  -yy            print ip:port pairs associated with socket file descriptors\n\
+  -yy            print protocol specific information associated with socket file descriptors\n\
 \n\
 Statistics:\n\
   -c             count time, calls, and errors for each syscall and report summary\n\