Fix for gcc15 breakage (Lukas Wirz)

https://bugs.launchpad.net/bugs/2096612

abi-compliance-checker:
Problems with Data Types
High 0
Medium 0
Low 1
filter.h
[+] typedef lmfunc 1
Change Effect
1 Base type has been changed from int(*)(...) to int(*)(int, int, double*, double*, int*). Recompilation of a client program may be broken.
[+] affected symbols: 26 (4.7%)

--- a/filter.h
+++ b/filter.h
@@ -410,7 +410,7 @@
 
 // function to minimize in Levenberg-Marquardt solver
 
-typedef		int (*lmfunc)();	
+typedef int (*lmfunc)(int m, int n, double x[], double fvec[], int *iflag);
 
 struct triangle
 {
@@ -774,13 +774,19 @@
 PANO13_IMPEX void 	matrix_inv_mult		( double m[3][3], double vector[3] );
 PANO13_IMPEX double 	smallestRoot		( double *p );
 PANO13_IMPEX void 	SetCorrectionRadius	( cPrefs *cP );
-PANO13_IMPEX int		lmdif				();
+PANO13_IMPEX int    lmdif(int m, int n, double x[], double fvec[],
+                          double ftol, double xtol, double gtol,
+                          int maxfev, double epsfcn, double diag[],
+                          int mode, double factor, int nprint,
+                          int *info, int *nfev, double fjac[],
+                          int ldfjac, int ipvt[], double qtf[],
+                          double wa1[], double wa2[], double wa3[], double wa4[]);
 PANO13_IMPEX void	fourier				( TrformStr *TrPtr, cPrefs *cP );
 PANO13_IMPEX unsigned short 	gamma_correct( double pix );
 PANO13_IMPEX int 	EqualCPrefs( cPrefs *c1, cPrefs *c2 );
 PANO13_IMPEX double 	OverlapRMS			( MultiLayerImage *mim );
 PANO13_IMPEX double 	distSquared			( int num ); 
-PANO13_IMPEX int		fcnPano();
+PANO13_IMPEX int    fcnPano(int m, int n, double x[], double fvec[], int *iflag);
 PANO13_IMPEX int		EvaluateControlPointError ( int num, double *errptr, double errComponent[2]);
 PANO13_IMPEX void 	doCoordinateTransform( CoordInfo *c, tMatrix *t );
 PANO13_IMPEX void 	findOptimumtMatrix( transformCoord *tP, tMatrix *tM, lmfunc f);