Fix ODR violation by excluding the correct paths.

nss.gyp

Index: nss.gyp
diff --git a/nss.gyp b/nss.gyp
index 6a4ef6d2b45e7d3e3ce9a9c1494ea1d67642ede5..2bc7f441144ec8006f018adf5847fc0ba3831d97 100644
--- a/nss.gyp
+++ b/nss.gyp
@@ -941,13 +941,13 @@
           'conditions': [
             ['target_arch=="x64" and OS!="win"', {
               'sources!': [
-                'nss/lib/freebl/chacha20/chacha20.c',
-                'nss/lib/freebl/poly1305/poly1305.c',
+                'nss/lib/freebl/chacha20.c',
+                'nss/lib/freebl/poly1305.c',
                 ],
             }, { # else: target_arch!="x64" or OS=="win"
               'sources!': [
-                'nss/lib/freebl/chacha20/chacha20_vec.c',
-                'nss/lib/freebl/poly1305/poly1305-donna-x64-sse2-incremental-source.c',
+                'nss/lib/freebl/chacha20_vec.c',
+                'nss/lib/freebl/poly1305-donna-x64-sse2-incremental-source.c',
                 ],
             }],
             ['OS=="ios"', {