Fix data race on cfiExportsMap

cfiExportsMap was reinitialized for every module, which caused
data races.  Create the path from the string on each use
instead.

Bug: 77234104
Test: m nothing with race detector turned on
Change-Id: Ibca3149dcbe8a9d4d9f7ec6dd0b164697e7ae5cd
diff --git a/cc/library.go b/cc/library.go
index bac566f..76f8a8c 100644
--- a/cc/library.go
+++ b/cc/library.go
@@ -532,6 +532,7 @@
 			flags.LdFlags = append(flags.LdFlags, "-Wl,--version-script,"+versionScript.String())
 			linkerDeps = append(linkerDeps, versionScript.Path())
 			if library.sanitize.isSanitizerEnabled(cfi) {
+				cfiExportsMap := android.PathForSource(ctx, cfiExportsMapPath)
 				flags.LdFlags = append(flags.LdFlags, "-Wl,--version-script,"+cfiExportsMap.String())
 				linkerDeps = append(linkerDeps, cfiExportsMap)
 			}