kpatch-build: fix Fedora 42+ kernel source directory nesting

Starting with Fedora 42, the kernel SRPM unpacks with an extra level
of nesting:

  BUILD/kernel-6.14.0-build/kernel-6.14/linux-6.14.0-63.fc42.x86_64/

The existing glob BUILD/kernel-*/linux-* only matches one level deep
and fails on this layout.

Use nullglob with a bash array to safely count flat-glob matches:
- Exactly one match: move it (traditional RHEL/CentOS/Fedora < 42).
- Multiple matches: die with a clear diagnostic.
- Zero matches: search one level deeper with find -maxdepth 3, again
  requiring exactly one result before proceeding.

All mv calls preserve the original "2>&1 | logger || die" error
handling, and ambiguous matches are always fatal.

Tested on Fedora 42 with kernel 6.14.0-63.fc42.x86_64.

Signed-off-by: Or Shoval <oshoval@redhat.com>
Co-authored-by: Cursor <cursoragent@cursor.com>

Author: oshoval

kpatch-build/kpatch-build

@@ -1082,7 +1082,28 @@ else
 		elif [[ "$DISTRO" = photon ]]; then
 			mv "$RPMTOPDIR"/BUILD/linux-"$KVER" "$KERNEL_SRCDIR" 2>&1 | logger || die
 		else
-			mv "$RPMTOPDIR"/BUILD/kernel-*/linux-* "$KERNEL_SRCDIR" 2>&1 | logger || die
+			# Fedora 42+ nests the source one level deeper:
+			#   BUILD/kernel-X.Y.Z-build/kernel-X.Y/linux-X.Y.Z-NN.fcNN.ARCH/
+			# Check the traditional flat layout first; if not found, search deeper.
+			shopt -s nullglob
+			LINUX_DIRS=( "$RPMTOPDIR"/BUILD/kernel-*/linux-* )
+			shopt -u nullglob
+			if [[ ${#LINUX_DIRS[@]} -eq 1 ]]; then
+				mv "${LINUX_DIRS[0]}" "$KERNEL_SRCDIR" 2>&1 | logger || die
+			elif [[ ${#LINUX_DIRS[@]} -gt 1 ]]; then
+				die "Multiple linux-* directories found in BUILD: ${LINUX_DIRS[*]}"
+			else
+				LINUX_SRC=$(find "$RPMTOPDIR/BUILD" -maxdepth 3 -type d -name "linux-*" \
+					! -path "*/configs/*")
+				MATCH_COUNT=$(echo "$LINUX_SRC" | grep -c . || true)
+				if [[ "$MATCH_COUNT" -eq 1 ]]; then
+					mv "$LINUX_SRC" "$KERNEL_SRCDIR" 2>&1 | logger || die
+				elif [[ "$MATCH_COUNT" -gt 1 ]]; then
+					die "Multiple linux source directories under $RPMTOPDIR/BUILD: $LINUX_SRC"
+				else
+					die "Could not find linux source directory under $RPMTOPDIR/BUILD"
+				fi
+			fi
 		fi
 
 		rm -rf "$RPMTOPDIR"