perf: Pass parameters by const reference to avoid copies

Fix cppcheck performance warnings by passing function parameters
by const reference instead of by value, preventing unnecessary
copies:
- string parameters in open_device_by_path()
- set<Connector*> parameters in connector finder functions
- vector parameter in FlipState constructor
- range variable in kmscapture loop

These changes improve performance by avoiding object copies while
maintaining the same functionality.

2 files changed, 2 insertions, 2 deletions

diff --git a/utils/kmscapture.cpp b/utils/kmscapture.cpp
index 23941ca..251cc3b 100644
--- a/utils/kmscapture.cpp
+++ b/utils/kmscapture.cpp
@@ -333,7 +333,7 @@ int main(int argc, char** argv)
 
 	vector<int> camera_fds;
 
-	for (string vidpath : glob("/dev/video*")) {
+	for (const string& vidpath : glob("/dev/video*")) {
 		int fd = ::open(vidpath.c_str(), O_RDWR | O_NONBLOCK);
 
 		if (fd < 0)
diff --git a/utils/kmstest.cpp b/utils/kmstest.cpp
index 43dc355..5028e7e 100644
--- a/utils/kmstest.cpp
+++ b/utils/kmstest.cpp
@@ -968,7 +968,7 @@ static bool max_flips_reached;
 class FlipState : private PageFlipHandlerBase
 {
 public:
-	FlipState(Card& card, const string& name, vector<const OutputInfo*> outputs)
+	FlipState(Card& card, const string& name, const vector<const OutputInfo*>& outputs)
 		: m_card(card), m_name(name), m_outputs(outputs)
 	{
 	}