[PATCH] ArmVirtPkg/PlatformPeiLib: add dummy assignment to work around older GCC

["Ard Biesheuvel" <ard.biesheuvel@linaro.org>]

Older GCC (<= 4.9) fail to infer that Parent is never used unless it
has been assigned before, and may throw an error like

  /work/git/edk2/ArmVirtPkg/Library/PlatformPeiLib/PlatformPeiLib.c:
      In function ‘PlatformPeim’:
  /work/git/edk2/ArmVirtPkg/Library/PlatformPeiLib/PlatformPeiLib.c:132:24:
      error: ‘Parent’ may be used uninitialized in this function
                                                [-Werror=maybe-uninitialized]
             RangesProp = fdt_getprop (Base, Parent, "ranges", &RangesLen);

Set Parent to 0 at the start of the sequence to work around this.

Link: https://bugzilla.tianocore.org/show_bug.cgi?id=2601
Fixes: 82662a3b5f56e974 ("ArmVirtPkg/PlatformPeiLib: discover the TPM base ...")
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
 ArmVirtPkg/Library/PlatformPeiLib/PlatformPeiLib.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/ArmVirtPkg/Library/PlatformPeiLib/PlatformPeiLib.c b/ArmVirtPkg/Library/PlatformPeiLib/PlatformPeiLib.c
index 8b5b3dd5dc1c..6c4028e17995 100644
--- a/ArmVirtPkg/Library/PlatformPeiLib/PlatformPeiLib.c
+++ b/ArmVirtPkg/Library/PlatformPeiLib/PlatformPeiLib.c
@@ -77,6 +77,11 @@ PlatformPeim (
 
   TpmBase = 0;
 
+  //
+  // Set Parent to suppress incorrect compiler/analyzer warnings.
+  //
+  Parent = 0;
+
   for (Prev = Depth = 0;; Prev = Node) {
     Node = fdt_next_node (Base, Prev, &Depth);
     if (Node < 0) {
-- 
2.17.1