ELS TLS documentation: s/module/module_id/.

The field is actually called `module_id` in the code.

Test: N/A
Change-Id: I10f5ce07cb67f7f338036c49e0008c3dce2db0bd
diff --git a/linker/arch/arm64/tlsdesc_resolver.S b/linker/arch/arm64/tlsdesc_resolver.S
index 96eff8e..ad155e2 100644
--- a/linker/arch/arm64/tlsdesc_resolver.S
+++ b/linker/arch/arm64/tlsdesc_resolver.S
@@ -58,9 +58,9 @@
   cmp x21, x22
   b.lo .fallback
 
-  ldr x21, [x0, #8]             // TlsIndex::module
+  ldr x21, [x0, #8]             // TlsIndex::module_id
   ldr x22, [x0, #16]            // TlsIndex::offset
-  ldr x21, [x20, x21, lsl #3]   // TlsDtv::modules[module]
+  ldr x21, [x20, x21, lsl #3]   // TlsDtv::modules[module_id]
   cbz x21, .fallback
   add x0, x21, x22
   sub x0, x0, x19