Minor changes to documentation and comments

Fix some typos and clarify some sentences.

Change-Id: Id276d1ced9a991b4eddc5c47ad9a825e6b29ef74
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>
diff --git a/include/lib/extensions/ras.h b/include/lib/extensions/ras.h
index 9f6b290..98daab6 100644
--- a/include/lib/extensions/ras.h
+++ b/include/lib/extensions/ras.h
@@ -106,7 +106,7 @@
 	 */
 	uint32_t syndrome;
 
-	/* For errors signalled via. interrupt, the raw interrupt ID; otherwise, 0. */
+	/* For errors signalled via interrupt, the raw interrupt ID; otherwise, 0. */
 	unsigned int interrupt;
 };
 
@@ -129,7 +129,7 @@
 	union {
 		struct {
 			/*
-			 * For a group accessed via. memory-mapped register,
+			 * For a group accessed via memory-mapped register,
 			 * base address of the page hosting error records, and
 			 * the size of the record group.
 			 */
@@ -141,7 +141,7 @@
 
 		struct {
 			/*
-			 * For error records accessed via. system register, index of
+			 * For error records accessed via system register, index of
 			 * the error record.
 			 */
 			unsigned int idx_start;