dccp: Toggle debug output without module unloading

This sets the sysfs permissions so that root can toggle the `debug'
parameter available for nearly every DCCP module. This is useful 
since there are various module inter-dependencies. The debug flag
can now be toggled at runtime using

  echo 1 > /sys/module/dccp/parameters/dccp_debug
  echo 1 > /sys/module/dccp_ccid2/parameters/ccid2_debug
  echo 1 > /sys/module/dccp_ccid3/parameters/ccid3_debug
  echo 1 > /sys/module/dccp_tfrc_lib/parameters/tfrc_debug

The last is not very useful yet, since no code at the moment calls
the tfrc_debug() macro.
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>

net/dccp/ccids/ccid2.c

@@ -783,7 +783,7 @@ static struct ccid_operations ccid2 = {
 };
 
 #ifdef CONFIG_IP_DCCP_CCID2_DEBUG
-module_param(ccid2_debug, bool, 0444);
+module_param(ccid2_debug, bool, 0644);
 MODULE_PARM_DESC(ccid2_debug, "Enable debug messages");
 #endif
 

net/dccp/ccids/ccid3.c

@@ -963,7 +963,7 @@ static struct ccid_operations ccid3 = {
 };
 
 #ifdef CONFIG_IP_DCCP_CCID3_DEBUG
-module_param(ccid3_debug, bool, 0444);
+module_param(ccid3_debug, bool, 0644);
 MODULE_PARM_DESC(ccid3_debug, "Enable debug messages");
 #endif
 

net/dccp/ccids/lib/tfrc.c

@@ -10,7 +10,7 @@
 
 #ifdef CONFIG_IP_DCCP_TFRC_DEBUG
 int tfrc_debug;
-module_param(tfrc_debug, bool, 0444);
+module_param(tfrc_debug, bool, 0644);
 MODULE_PARM_DESC(tfrc_debug, "Enable debug messages");
 #endif
 

net/dccp/proto.c

@@ -1030,7 +1030,7 @@ MODULE_PARM_DESC(thash_entries, "Number of ehash buckets");
 
 #ifdef CONFIG_IP_DCCP_DEBUG
 int dccp_debug;
-module_param(dccp_debug, bool, 0444);
+module_param(dccp_debug, bool, 0644);
 MODULE_PARM_DESC(dccp_debug, "Enable debug messages");
 
 EXPORT_SYMBOL_GPL(dccp_debug);