[PATCH bpf-next] libbpf: fix Makefile exit code if libelf not found

[Jakub Kicinski <jakub.kicinski@netronome.com>]

/bin/sh's exit does not recognize -1 as a number, leading to
the following error message:

/bin/sh: 1: exit: Illegal number: -1

Use 1 as the exit code.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
---
 tools/lib/bpf/Makefile | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile
index 4555304dc18e..8ed43ae9db9b 100644
--- a/tools/lib/bpf/Makefile
+++ b/tools/lib/bpf/Makefile
@@ -213,10 +213,10 @@ PHONY += force elfdep bpfdep
 force:
 
 elfdep:
-	@if [ "$(feature-libelf)" != "1" ]; then echo "No libelf found"; exit -1 ; fi
+	@if [ "$(feature-libelf)" != "1" ]; then echo "No libelf found"; exit 1 ; fi
 
 bpfdep:
-	@if [ "$(feature-bpf)" != "1" ]; then echo "BPF API too old"; exit -1 ; fi
+	@if [ "$(feature-bpf)" != "1" ]; then echo "BPF API too old"; exit 1 ; fi
 
 # Declare the contents of the .PHONY variable as phony.  We keep that
 # information in a variable so we can use it in if_changed and friends.
-- 
2.15.1