Don't allow creation of fifo when opening since it should already exist

Change-Id: Ieb486d882f89daea1d6d48bc46c0006e7ff04a68

src/emit.c

diff --git a/src/emit.c b/src/emit.c
index 92e8c96..61d09cc 100644
--- a/src/emit.c
+++ b/src/emit.c
@@ -63,7 +63,7 @@
 {
 	const char *fifo = mygetenv(ENV_FIFO_PATH);
 	assert(fifo);
-	if ((write_fd = open(fifo, O_CREAT | O_WRONLY)) < 0) {
+	if ((write_fd = open(fifo, O_WRONLY)) < 0) {
 		error("emitInit failed to open %s", fifo);
 		return  -1;
 	}

src/unix/proc.c

diff --git a/src/unix/proc.c b/src/unix/proc.c
index 5eb8d3b..e706d9b 100644
--- a/src/unix/proc.c
+++ b/src/unix/proc.c
@@ -193,7 +193,7 @@
 		size_t sz;
 		char   c;
 
-		const int fd = open(fifo, O_CREAT | O_RDONLY);
+		const int fd = open(fifo, O_RDONLY);
 		if (fd < 0) {
 			error("failed to open fifo %s for read");
 			return ERR_PROC_UNKNOWN;