libkmod-module: Don't pass NULL pointer to memcpy

When passing n=0, don't pass a NULL pointer, but instead pass anything
else (like the pointer to the start of the string).
diff --git a/CODING-STYLE b/CODING-STYLE
index e60df9e..865252e 100644
--- a/CODING-STYLE
+++ b/CODING-STYLE
@@ -15,10 +15,12 @@
 character per line limit.  This is generally only allowed if the alternative
 would make the code even less readable.
 
-Besides the kernel coding style above, kmod coding style is havily based on
+Besides the kernel coding style above, kmod coding style is heavily based on
 oFono's and BlueZ's. Below some basic rules:
 
-1) Wrap line at 80 char limit. There are a few exceptions:
+1) Wrap line at 80 char limit.
+
+There are a few exceptions:
 	- Headers may or may not wrap
 	- If it's a string that is hitting the limit, it's preferred not to break
 	  in order to be able to grep for that string. E.g:
@@ -29,6 +31,9 @@
 	- If there's only one argument to the function, don't put it alone in a
 	  new line.
 
+Align the wrapped line either with tabs (BlueZ, oFono, etc) or tab + spaces
+(kernel), at your discretion. Kernel's is preferred.
+
 2) It's better to return/exit early in a function than having a really long
    "if (...) { }". Example: