Fix bustage (really?) since NSPR defines ALIGN_OF_WORD to PR_ALIGN_OF_WORD even when PR_ALIGN_OF_WORD isn't defined.

modules/libpref/src/prefapi.cpp

@@ -180,20 +180,20 @@ static PLDHashTableOps     pref_HashTableOps = {
     
 class PrefNameBuffer;
 
-#ifdef PR_ALIGN_OF_WORD
+// PR_ALIGN_OF_WORD is only defined on some platforms.  ALIGN_OF_WORD has
-#define ALIGN_OF_WORD PR_ALIGN_OF_WORD
+// already been defined to PR_ALIGN_OF_WORD everywhere
-#else
+#ifndef PR_ALIGN_OF_WORD
-#define ALIGN_OF_WORD sizeof(void*)
+#define PR_ALIGN_OF_WORD sizeof(void*)
 #endif
 
 // making PrefNameBuffer exactly 8k for nice allocation
 #define PREFNAME_BUFFER_LEN (8192 - (sizeof(PrefNameBuffer*) + sizeof(char*)))
 
-#define WORD_ALIGN_MASK (ALIGN_OF_WORD - 1)
+#define WORD_ALIGN_MASK (PR_ALIGN_OF_WORD - 1)
 
 // sanity checking
-#if (ALIGN_OF_WORD & WORD_ALIGN_MASK) != 0
+#if (PR_ALIGN_OF_WORD & WORD_ALIGN_MASK) != 0
-#error "ALIGN_OF_WORD must be a power of 2!"
+#error "PR_ALIGN_OF_WORD must be a power of 2!"
 #endif
 
 class PrefNameBuffer {