efi_loader: fix ipv4 device path node conversion

When converting an IPv4 device path node to text, the
EFI_DEVICE_PATH_TO_TEXT_PROTOCOL will produce the following string:

  IPv4(5.6.7.8,TCP,UDP,0x6,DHCP,1.2.3.4,9.10.11.12,255.255.255.0)

This string erroneously contains multiple protocols: TCP, UDP and 0x6.

Add the missing `break' statements in the dp_msging() function to fix this
and obtain the following expected string instead:

  IPv4(5.6.7.8,TCP,DHCP,1.2.3.4,9.10.11.12,255.255.255.0)

Fixes: aaf63429a112 ("efi_loader: add IPv4() to device path to text protocol")
Signed-off-by: Vincent Stehlé <vincent.stehle@arm.com>
Cc: Heinrich Schuchardt <xypron.glpk@gmx.de>
Cc: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Cc: Adriano Cordova <adrianox@gmail.com>
Cc: Tom Rini <trini@konsulko.com>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
diff --git a/lib/efi_loader/efi_device_path_to_text.c b/lib/efi_loader/efi_device_path_to_text.c
index f6889cb..452ec1b 100644
--- a/lib/efi_loader/efi_device_path_to_text.c
+++ b/lib/efi_loader/efi_device_path_to_text.c
@@ -181,10 +181,13 @@
 		switch (idp->protocol) {
 		case IPPROTO_TCP:
 			s += sprintf(s, "TCP,");
+			break;
 		case IPPROTO_UDP:
 			s += sprintf(s, "UDP,");
+			break;
 		default:
 			s += sprintf(s, "0x%x,", idp->protocol);
+			break;
 		}
 		s += sprintf(s, idp->static_ip_address ? "Static" : "DHCP");
 		s += sprintf(s, ",%pI4", &idp->local_ip_address);