Fix Typo in shmem_alltoall

Author: kwaters4

content/shmem_alltoall.tex

@@ -35,7 +35,7 @@
 
 \apiargument{OUT}{dest}{Symmetric address of a data object large enough to receive
     the combined total of \VAR{nelems} elements from each \ac{PE} in the
-    particpating \acp{PE}.
+    participating \acp{PE}.
     The type of \dest{} should match that implied in the SYNOPSIS section.}
 \apiargument{IN}{source}{Symmetric address of a data object that contains \VAR{nelems}
     elements of data for each \ac{PE} in the participating \acp{PE}, ordered according to