[OpenMP] NFC: Fix trivial typos in comments

Submitted by: kiszk

Differential Revision: https://reviews.llvm.org/D72171
diff --git a/openmp/runtime/src/kmp_alloc.cpp b/openmp/runtime/src/kmp_alloc.cpp
index 8619401..16893d0 100644
--- a/openmp/runtime/src/kmp_alloc.cpp
+++ b/openmp/runtime/src/kmp_alloc.cpp
@@ -57,7 +57,7 @@
    multiple of this size.  This MUST be a power of two. */
 
 /* On IA-32 architecture with  Linux* OS, malloc() does not
-   ensure 16 byte alignmnent */
+   ensure 16 byte alignment */
 
 #if KMP_ARCH_X86 || !KMP_HAVE_QUAD