doc: Fix two typos in coding-style.txt

Signed-off-by: Niels Thykier <niels@thykier.net>
Signed-off-by: Guillem Jover <guillem@debian.org>

doc/coding-style.txt

@@ -28,12 +28,12 @@ Code should generally strive for clarity. Monster functions should be split
 into logical and small pieces.
 
 Variable and function names should be generally descriptive, not needed
-for variables commonly used (for example and index inside a loop, etc),
+for variables commonly used (for example an index inside a loop, etc),
 acronyms should only be used if they are widely known externally or
 inside the project. The names should separate logical concepts within
 with underscores.
 
-On comments use UTF-8 characters for quotes, copyrigth symbols, etc.
+On comments use UTF-8 characters for quotes, copyright symbols, etc.
 
 On strings in code use simple or double quotes «''» «""». Not the unpaired
 ones «`'». Strings marked for translation, should only be fixed if there's