Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
diff --git a/arch/s390/include/asm/atomic.h b/arch/s390/include/asm/atomic.h
index 5c5ba10..d9db138 100644
--- a/arch/s390/include/asm/atomic.h
+++ b/arch/s390/include/asm/atomic.h
@@ -9,7 +9,7 @@
  *
  * Atomic operations that C can't guarantee us.
  * Useful for resource counting etc.
- * s390 uses 'Compare And Swap' for atomicity in SMP enviroment.
+ * s390 uses 'Compare And Swap' for atomicity in SMP environment.
  *
  */